JP7202948B2 - Gas leak inspection method and gas leak inspection device - Google Patents

Description

The present invention relates to a gas leakage inspection method and a gas leakage inspection device.

Conventionally, for example, in a unit cell of a solid polymer fuel cell, a gas diffusion Fuel gas and oxygen or air as an oxidant are introduced from the reactant gas flow path of each separator through the layers. A fuel gas is introduced to the anode and oxygen or air is introduced to the cathode. Hydrogen, for example, is used as the fuel gas (see Patent Document 1, for example). Also, a sealing material is used to suppress leakage of hydrogen.

JP 2005-276729 A

As described above, since hydrogen, for example, is introduced as a fuel gas into the anode of the unit cell of the polymer electrolyte fuel cell, it is necessary to measure leakage of the fuel gas by pressure inspection. Since hydrogen molecules are small in size, they permeate the sealing material, albeit in a very small amount. For this reason, fuel gas leaks are caused by permeation of the seal material and by gaps between the seal material and other members. However, it was not possible to determine whether the leakage occurred from the gap between the sealing material and other members, and there was no choice but to evaluate the total amount of leakage (leak amount).

For this reason, it is not possible to evaluate the amount of permeation and the amount of leakage, and at the shipping stage of a product equipped with a polymer electrolyte fuel cell, there is a requirement that hydrogen does not leak from the product and that only the sealing material permeates. Cannot set. As a result, it is necessary to conduct a durability test of permeation amount over time, which requires a large number of man-hours.

The present invention provides a gas leakage inspection method and a gas leakage inspection device that can distinguish whether fuel gas leakage is due to permeation of the sealing material or due to a gap between the sealing material and other members. intended to provide

In order to achieve the above object, the present invention introduces a gas to be inspected into the inside of a member to be inspected (for example, a fuel cell 10 to be described later), and provides a sealing material (for example, a sealing material to be described later) for sealing the member to be inspected. 101) is a gas leakage inspection method for measuring gas to be inspected to the outside to inspect gas leakage to the outside of the sealing material, wherein the measuring step comprises measuring the gas leakage to the outside of the sealing material in chronological order. a gas quantity measuring step of measuring a gas quantity; determining a leak state in which there is a gap between the gas leakage and the sealing material, and determining a permeation state in which the gas to be inspected is permeating through the sealing material when the gap is equal to or less than the predetermined value. Provide an inspection method.

According to the present invention, it is possible to determine whether leakage occurs or only transmission occurs after a predetermined period of time has elapsed. For this reason, it is possible to determine the quality of each of the permeation amount regulation and the leakage amount regulation by performing the inspection once, and at the shipping stage of the product including the inspection object parts, the inspection target gas is not leaked from the product. It is possible to set the requirement that only the sealant permeates. As a result, it is possible to relax the permeation amount aging test in the endurance test, and to reduce the man-hours of the endurance test.

In addition, the present invention introduces a gas to be inspected into the inside of a member to be inspected (for example, a fuel cell 10 described later), and the outside of a sealing material (for example, a sealing material 101 to be described later) that seals the member to be inspected. A gas leakage inspection method for inspecting gas leakage to the outside of the sealing material by measuring a gas to be inspected to the sealing material, wherein the measuring step measures the amount of gas flowing to the outside of the sealing material in chronological order. and when an inflection point is detected in the inclination of the gas amount to the outside per unit time in a time zone near a predetermined time after the introduction of the inspection object gas, the inspection object gas is detected. a determination step of determining that the gas leak inspection is in both a leak state in which there is a gap between the target member and the sealing material, and a permeation state in which the gas to be inspected is permeating through the sealing material. provide a way.

According to the present invention, it can be determined that the state is in both the leak state and the transmission state in a time zone near a predetermined time. As a result, the leak state and the permeation state can be determined more reliably, and it is possible to determine whether the fuel gas leak is due to permeation of the seal material or due to a gap between the seal material and other members. Separation becomes possible.

In the gas amount measuring step, the pressure of the gas to be inspected outside the sealing material is measured so as to airtightly surround the member to be inspected provided with the sealing material, and the gas outside the sealing material is measured. Check for leaks.

Therefore, by airtightly surrounding a member to be inspected provided with a sealing material and measuring the pressure of the gas to be inspected outside the sealing material, the gas to be inspected in the member to be inspected can be permeated by a simple method. It is possible to determine the quality of each of the amount regulation and the leakage amount regulation.

Further, the present invention includes a gas introduction portion for introducing a gas to be inspected into the inside of a member to be inspected (for example, a fuel cell 10 described later), and a sealing material for sealing the member to be inspected (for example, a sealing material to be described later). 101), and a gas measurement unit (for example, a pressure gauge 22 to be described later) for measuring the gas to be inspected to the outside of the gas leakage inspection device (for example, the gas leakage inspection device 1 to be described later), wherein the gas measurement The part measures the amount of gas to the outside of the sealing material in chronological order, and when the amount of gas to the outside per unit time after the passage of a predetermined time from the introduction of the gas to be inspected is greater than a predetermined value a leak state in which there is a gap between the member to be inspected and the seal material, and when the gap is equal to or less than the predetermined value, a permeation state in which the inspection target gas is transmitted through the seal material is determined. A gas leak inspection device is provided that includes a determination unit (for example, a determination unit 51 to be described later).

According to the present invention, it is possible to determine whether leakage occurs or only transmission occurs after a predetermined period of time has elapsed. For this reason, it is possible to determine the quality of each of the permeation amount regulation and the leakage amount regulation by performing the inspection once, and at the shipping stage of the product including the inspection object parts, the inspection target gas is not leaked from the product. It is possible to set the requirement that only the sealant permeates. As a result, it is possible to relax the permeation amount aging test in the endurance test, and to reduce the man-hours of the endurance test.

In addition, the present invention includes a gas introduction portion for introducing a gas to be inspected into the inside of a member to be inspected (for example, a fuel cell 10 described later), and a seal (for example, a sealing material 101 to be described later) for sealing the member to be inspected. ) gas measurement unit for measuring the gas to be inspected to the outside of the sealing material (for example, the gas leakage inspection device 1 described later), wherein the gas measurement unit measures the sealing material in chronological order. is measured, and an inflection point is detected in the slope of the outward gas amount per unit time in a time zone near a predetermined time after the gas to be inspected is introduced, A determination unit (for example, a A gas leak inspection device is provided that includes a determination unit 51).

According to the present invention, it can be determined that the state is in both the leak state and the transmission state in a time zone near a predetermined time. As a result, the leak state and the permeation state can be determined more reliably, and it is possible to determine whether the fuel gas leak is due to permeation of the seal material or due to a gap between the seal material and other members. Separation becomes possible.

The gas measuring unit airtightly surrounds the member to be inspected, measures the pressure of the gas to be inspected outside the sealing material, and inspects gas leakage outside the sealing material. section (for example, a sealing material outer inspection section 11 to be described later).

For this reason, a sealing member outer inspection portion is provided so as to airtightly surround a member to be inspected including the sealing member, and the pressure of the inspection target gas is measured in the sealing member outer inspection portion outside the sealing member. As a result, it is possible to determine whether the gas to be inspected in the member to be inspected is passable or not with respect to both the permeation amount regulation and the leak amount regulation by a simple method.

According to the present invention, a gas leakage inspection method and a gas leakage inspection capable of distinguishing whether fuel gas leakage is due to permeation of the sealing material or due to a gap between the sealing material and another member. Equipment can be provided.

1 is a schematic diagram showing a gas leak inspection device according to an embodiment of the present invention; FIG. 1 is a block diagram showing a gas leak inspection device according to one embodiment of the present invention; FIG. It is a figure explaining the leak detected by the gas leak inspection apparatus by one Embodiment of this invention. It is a figure explaining permeation|transmission detected by the gas leak test|inspection apparatus by one Embodiment of this invention. 4 is a graph explaining the difference between leak and permeation detected by the gas leak inspection device according to the embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a gas leak inspection device 1. As shown in FIG. FIG. 2 is a block diagram showing the gas leak inspection device 1. As shown in FIG. FIG. 3 is a diagram for explaining leaks detected by the gas leak inspection device 1. FIG. FIG. 4 is a diagram for explaining permeation detected by the gas leak inspection device 1. FIG. FIG. 5 is a graph for explaining the difference between leak and permeation detected by the gas leak inspection device 1. FIG.
A gas leak inspection device is a device for detecting leakage of hydrogen gas in a fuel cell system. The gas leakage inspection device 1 and the fuel cell system to be inspected by the gas leakage inspection device will be described below.

The fuel cell system includes a fuel cell 10 that generates electricity by reacting hydrogen gas as an anode gas and air as a cathode gas, a hydrogen gas supply device 30 that supplies hydrogen gas to the fuel cell 10, and the fuel cell 10. It has an air supply device (not shown) that supplies air to and a control device 50 that controls them.
In addition, the gas leak inspection device includes a gas introduction section configured by the hydrogen gas supply device 30, a gas measurement section configured by the pressure gauges 21 and 22, a determination section 51 configured by the control device 50, and a sealing material and an outer inspection section 11 .

The fuel cell 10 has, for example, a stack structure in which tens to hundreds of cells are stacked. Each cell is configured by sandwiching a membrane electrode assembly (MEA) between a pair of separators. A membrane electrode assembly is composed of two electrodes, an anode electrode and a cathode electrode, and a solid polymer electrolyte membrane sandwiched between these electrodes. Both electrodes are generally formed of a catalyst layer that is in contact with the solid polymer electrolyte membrane and performs an oxidation/reduction reaction, and a gas diffusion layer that is in contact with this catalyst layer.

In such a fuel cell 10, hydrogen gas is supplied to an anode flow path formed on the anode electrode side, and air containing oxygen is supplied to a cathode flow path (not shown) formed on the cathode electrode side. Electricity is generated by an electrochemical reaction.

A hydrogen tank 32 constituted by a cylinder supplies hydrogen gas to the anode channel of the fuel cell 10 via a hydrogen supply channel 35 as an anode gas supply channel. In the portion of the hydrogen supply path 35 between the hydrogen tank 32 and the fuel cell 10, a regulator 31 for reducing the pressure of the hydrogen gas supplied from the hydrogen tank 32 and a pressure gauge 21 are arranged in this order in the flow of hydrogen gas. It is provided from the upstream side to the downstream side.

The other end of the anode channel of the fuel cell 10 is connected to a diluter (not shown) via a back pressure valve 12 that opens and closes the anode channel. By opening the back pressure valve 12, the gas flowing through the other end of the anode channel can be discharged to the diluter at a medium flow rate.

A diluter (not shown) dilutes the hydrogen off-gas introduced into the diluter and releases it to the outside of the fuel cell system.

The sealing material outer inspection part 11 is configured by a container that airtightly surrounds the fuel cell 10 .

A pressure gauge 21 measures the pressure of the hydrogen gas reduced by the regulator 31 . The pressure gauge 21 is electrically connected to the control device 50, and the control device 50 calculates the amount of hydrogen gas flowing from the regulator 31 to the fuel cell 10 based on the pressure value measured by the pressure gauge 21. be done.

The pressure gauge 22 measures the pressure of the hydrogen gas inside the sealing material outer inspection portion 11 . The pressure gauge 22 is electrically connected to the control device 50 , and the control device 50 determines the amount of hydrogen gas inside the sealing material outer inspection portion 11 based on the pressure value measured by the pressure gauge 22 . Calculated.

The control device 50 has a determination section 51 . Based on the amount of hydrogen gas inside the sealing material outer inspection unit 11 based on the pressure value measured by the pressure gauge 22, the determination unit 51 determines that a predetermined time t1 has elapsed since the hydrogen gas as the gas to be inspected was introduced. Later, when the amount of hydrogen gas per unit time to the outside of the fuel cell 10 and the sealing material 101 of the fuel cell 10 and to the inside of the sealing material outside inspection part 11 is larger than a predetermined value, the object to be inspected 3 between the member 102 and the member 103 constituting the fuel cell 10 and the sealing member 101. When the gap is below a predetermined value, it is determined that there is a leak as shown in FIG. It is determined that the sealing material 101 is in a permeable state in which there is no gap as shown in FIG. The details of this determination will be described later.

Next, a gas leak inspection method will be described.
First, as shown in FIG. A graph of the permeation amount of hydrogen gas is obtained in advance when hydrogen gas is permeated in a state where there is no gap between the . Specifically, a straight line graph of “transmission” in FIG. 5 is obtained in advance.

Next, hydrogen gas, which is the gas to be inspected, is introduced from the hydrogen tank 32 into the inside (inside) of the fuel cell 10, which is the member to be inspected. Then, the gas amount measurement process is performed. In the gas amount measurement process, the pressure outside the sealing material 101, that is, outside the fuel cell 10 hermetically accommodated by the sealing material outside inspection part 11 and inside the sealing material outside inspection part 11 is measured in time series. Thus, the amount of hydrogen gas to the outside of the sealing material 101 per unit time is measured.

That is, in the sealing material 101 provided in the fuel cell 10 airtightly accommodated by the sealing material outer inspection section 11, as described above, the slope of the straight line of the permeation amount of hydrogen gas ("permeation requirement ) is constant. In addition, as shown in FIG. 4, there is no gap between the sealing material 101 and the member 103 that constitutes the fuel cell 100. Therefore, the hydrogen gas does not leak and permeates the sealing material 101. 5, permeation of hydrogen gas occurs during the period from the start of introduction of hydrogen gas from the hydrogen tank 32 until the predetermined time t1 elapses, as shown in the graph of "permeation" in FIG. Absent.

On the other hand, as shown in FIG. 3, for example, when there is a gap between the sealing material 101 and the member 103 constituting the fuel cell 100, the graph of "leakage" in FIG. Thus, at the same time that hydrogen gas starts to be introduced from the hydrogen tank 32 , the hydrogen gas starts to leak outside the sealant 101 and into the sealant outside inspection section 11 . Therefore, as shown in FIG. 3, when there is a gap between the sealing material 101 and the member 103 that constitutes the fuel cell 100, the graph of the hydrogen gas leakage amount is different from the graph of FIG. There will be an inflection point as shown in the graph of +transmission.

Next, a determination process based on the drawn graph is performed. In the determination step, when the amount of gas flowing outward per unit time after a predetermined time t1 has elapsed from the introduction of the hydrogen gas is larger than a predetermined value (the amount of permeation of the hydrogen gas through the sealing material 101 per unit time), That is, after the predetermined time t1, when the slope of the obtained hydrogen gas leak amount graph is larger than the slope of the graph of the "permeation requirement (permeation)" in FIG. It is determined that there is a gap between and is in a leak state. On the other hand, when the amount of gas to the outside per unit time after the lapse of the predetermined time t1 from the introduction of the hydrogen gas is equal to or less than a predetermined value (amount of permeation of the hydrogen gas through the sealing material 101 per unit time), that is, a predetermined After time t1, when the slope of the graph of the obtained hydrogen gas leakage amount is equal to or less than the slope of the graph of "permeation requirement (permeation)" in FIG. It is determined that the hydrogen gas is permeating only through the sealing material 101 without any gap between them.
In consideration of design errors of the fuel cell and the sealing material, the leak state or the permeation state may be determined by detecting the inflection point shown in the above-described "leakage + permeation" graph. Specifically, in the determination step, the amount of gas to the outside per unit time after a predetermined time t1 has elapsed since the introduction of the hydrogen gas is obtained in chronological order, and in a time zone near the predetermined time t1, the obtained When the slope of the hydrogen gas leak amount graph is larger than the slope of the "permeation requirement (permeation)" graph in FIG. 5 and the inflection point shown in the "leak + permeation" graph is detected , it is determined that there is a gap between the member 103 and the sealing material 101, and that both the leak state and the transmission state are present. By doing so, it is possible to more reliably determine the leak state and the transmission state.

According to this embodiment, the following effects are achieved.
In the gas leak inspection method according to the present embodiment, when the amount of gas to the outside per unit time after a predetermined time t1 has elapsed since hydrogen gas was introduced as the inspection target gas is larger than a predetermined value, the inspection target member and determining a leakage state in which there is a gap between the member 103 and the sealing material 101, and determining a permeation state in which hydrogen gas is permeating through the sealing material 101 when the gap is equal to or less than a predetermined value. .
Further, the gas leak inspection apparatus according to the present embodiment detects when the amount of gas flowing to the outside per unit time after the predetermined time t1 has elapsed since the introduction of the hydrogen gas as the gas to be inspected is greater than a predetermined value. A judgment unit that judges that there is a leak state in which there is a gap between the member 103 as a member to be inspected and the sealing material 101, and judges that it is in a permeation state that hydrogen gas is permeating through the sealing material 101 when the gap is equal to or less than a predetermined value. Prepare.

This makes it possible to determine whether leakage occurs or only transmission occurs after the predetermined time t1 has elapsed. For this reason, it is possible to determine whether the permeation amount regulation and the leakage amount regulation are satisfied by conducting a single inspection, and at the shipping stage of products equipped with polymer electrolyte fuel cells, it is possible to check whether hydrogen is leaking from the product. First, it is possible to set a requirement that there is only transmission through the sealant 101 . As a result, it is possible to relax the permeation amount aging test in the endurance test, and to reduce the man-hours of the endurance test. Furthermore, as shown in FIG. 5, even when the leak amount (slope a<slope c) is smaller than the leak amount in the permeation state, it is possible to determine the leak state in which there is a gap between the member 103 and the sealing material 101. can.

Further, in the gas amount measuring step of the gas leakage inspection method according to the present embodiment, the pressure of hydrogen gas as the inspection target gas outside the sealing material 101 is measured to inspect gas leakage outside the sealing material 101 . In addition, the gas measurement unit of the gas leakage inspection device according to the present embodiment is provided with a sealing material outer inspection part that airtightly surrounds the member to be inspected, and measures the pressure of hydrogen gas outside the sealing material 101 to A sealing material outer inspection part for inspecting the outside of 101 for gas leakage is provided.

As a result, the sealant outer inspection section 11 is provided so as to airtightly surround the fuel cell 10 having the sealant 101, and the pressure inside the sealant outer inspection section 11 outside the sealant 101 is measured. As a result, it is possible to judge whether the hydrogen gas in the fuel cell 10 is good or bad with respect to both the permeation amount regulation and the leakage amount regulation by a simple method.

The present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.
For example, the present invention can be suitably used for fuel cells other than polymer electrolyte fuel cells and other gas utilization devices as objects to be inspected. Similarly, it can be suitably used for leak detection of gases other than hydrogen gas as inspection target gases.
For example, in the gas leak inspection method according to the present embodiment, the pressure of hydrogen gas as the inspection target gas outside the sealing material 101 is measured. Although the pressure of hydrogen gas as gas was measured to check for gas leakage outside the sealing material 101, the configuration is not limited to this. For example, it may be determined that the hydrogen gas has permeated or leaked by detecting the reduced amount of hydrogen gas in the hydrogen tank 32, or the gas amount may be measured by a method other than pressure.
Further, in the above-described embodiment, in the determination step, when the slope of the hydrogen gas leak amount graph is equal to or greater than a predetermined value and an inflection point is detected, it is determined that both the leak state and the permeation state are present. However, after the hydrogen gas, which is the gas to be inspected, was introduced from the hydrogen tank 32 into the inside (inside) of the fuel cell 10, which is the member to be inspected, during a period of time near the predetermined time t1, the above-described "leakage Both the leak state and the transmission state may be determined only by detecting the inflection point shown in the graph of +transmission.

REFERENCE SIGNS LIST 1 gas leak inspection device 10 fuel cell 11 sealing material outer inspection unit 21 pressure gauge 22 pressure gauge 30 hydrogen gas supply device 31 regulator 32 hydrogen tank 51 determining unit 101 sealing material

Claims (4)

introducing a gas to be inspected inside the member to be inspected,
A gas leakage inspection method for inspecting gas leakage to the outside of the sealing material by measuring the inspection target gas to the outside of the sealing material that seals the inspection target member,
The step of measuring includes a gas amount measuring step of measuring the amount of gas flowing to the outside of the sealing material in chronological order;
When an inflection point is detected in the slope of the outward gas amount per unit time in a period of time near a predetermined time after the inspection target gas is introduced, the inspection target member and the sealing material are detected. a determination step of determining that both a leak state in which there is a gap therebetween and a permeation state in which the gas to be inspected is permeating through the sealing material. In the gas amount measuring step, the pressure of the gas to be inspected outside the sealing material is measured so as to airtightly surround the member to be inspected provided with the sealing material, and gas leakage outside the sealing material is detected. The gas leak inspection method according to claim 1 , wherein the inspection is performed. a gas introduction unit that introduces the gas to be inspected into the inside of the member to be inspected;
A gas leakage inspection device comprising: a gas measuring unit for measuring a gas to be inspected to the outside of a sealing material that seals the member to be inspected,
The gas measurement unit measures the amount of gas to the outside of the sealing material in chronological order,
When an inflection point is detected in the slope of the outward gas amount per unit time in a period of time near a predetermined time after the inspection target gas is introduced, the inspection target member and the sealing material are detected. A gas leak inspection device comprising a determination unit that determines both a leak state in which there is a gap and a permeation state in which the gas to be inspected is permeated through the sealing material. The gas measurement unit includes a seal material outer inspection unit that airtightly surrounds the member to be inspected, measures the pressure of the inspection target gas outside the seal material, and inspects gas leakage outside the seal material. The gas leak inspection device according to claim 3 .

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